Found some fascinating posts on Youtube recently.
They're raw, amateur, spontaneous recordings taken down by the Belt Parkway/Bike Path on September 11, 2001.
Spectators gather by the bike bath near the Belt Parkway on the September 11, after the Towers were hit
At the overpass over the Belt Parkway, an eyewitness speaks of seeing United Airlines 175 fly overhead, before it crashed into Two World Trade Center.
The South Tower ( Two WTC ) burns
From the overpass, you see large crowds on the 69th Street Pier, and in the distance you see the smoke from the Towers...and, thankfully obscured by the smoke, the second tower falls.
I think that we'll be learning new details on this for the rest of our lives.